Process for coating and sealing red cedar lumber to prevent the escape of cedar aroma



Patented Apr. 4, 1933 UNITED STATES,

PATENT OFFICE FRANK BABAK, 0] WASHINGTON, DISTRICT OF COLUMBIA,DEDICATED TO THE AND THE PEOPLE OF THE UNITED STATES OF AMERICA PROCESSFOR COATING AND SEALING RED CEDAR LUMBER TO PREVENT THE ESCAPE OI CEDARAROMA No Drawing.

Application filed August 2, 1930. Serial No. 472,742.

(enman wanna 'ma ACT or Manon a, less, asv manner man. 30, 1928; 370 o.e. as?

scribed to the free use of the public to take effect upon the grantingof a patent to me.

The use of cedar, particularly red cedar,

) for the manufacture of containers for clothing, particularly cedarchests and cedar closets in homes, has come to be quite extensivebecause of the efficacy of the aroma in preventing moths from inhabitingand destroying or injuring articles of clothing stored in suchcontainers. Because of the comparative scarcity of red cedar and theconsequent cost of same, closets and chests for the purpose stated arenow commonly lined with the red cedar wood and the manufacture and saleof cedar closet lining has come to be an industry of considerableproportions in this country. The red cedar is out. into boards or stripsofappropriate thickness and with, say approximately in thickness by 2 inwidth with the edges formed to be interengaged by tongue-and-grooveformation. The eflicienc of the red cedar for the purpose mentionedmaximum concentration of cedar aroma or vapor within the closet orchest. The aroma or vapor from the cedar is produced by volatilizati'on'of the emential oil contained in the wood. As the result of experimentsextending over a considerable period of time, I, have discovered thatwhen cedar' boards are exposed to the air there is a loss of oil byvola- 40 tilization, which loss is proportionate to the thicknessof theboards and the length'of time exposed. Cedar boards exhale aroma andthereby lose oil from all exposed surfaces As will be readily understoodthe aroma exhaled from the exterior surface of the board is lost. Inorder to conserve the volatile oil it is important that loss from suchexterior surfaces'be revented. In cedar chests this is sometimes 1n ameasureaccom plished by the finishing coating on the exterior of thecedar. In cedar closets, how

is dependent upon the ever, which are constructed by boarding up theside Walls and ceiling with the cedar boards attached directly to thestuds and joists such loss from the exterior surfaces is material andall waste, with the resulting efliciency of the closet for-thepurposesintended greatly depreciated.

Since the cedar boards exhale aroma from all exposed surfaces it will bereadily understood that the exterior surface gives off the aroma in thesame, volume as the interior surface: The aroma-volatilized from theexterior of the boards is practically lost to the interior of thecloset. For "the purpose of conserving the aroma and prolonging theefficiency of the closet, chest or other container lined with the cedar,these experiments have been conducted to discovera material method ofapplication. In planning the pro:

cedure for the experiments several important points were regarded asentitled to particular consideration as follows: 1) Effective sealing ofthe exterior to prevent any escape of oil (cedar aroma) in thatdirection. 7

(2) A coating that would be transparent and with no covering power inorder that it could be observed by a glance that the boards were'of redheart wood only, the type of wood recognized as most eflicient for thepurpose. (3) A coating that should permit of easy application and dryquickly and permanently.

(4) Acoating that after being applied to the boards should be free fromall stickiness or tackiness in order that the boards might be packed inbundles without adhering to each other, as in making up packages forshipment and handling as -an article of commence. l I

(5) Low cost of the material and of the application of the same to theboards.

order to effectively seal the wood toit should combine transparency andrapid drying qualities, lack of stickiness and low cost.

The following materials have been used in my experiments:

Orange sheZZac.-A varnish pre ared by dissolving orange shellac inenatured alcohol. A commercial product obtainable in the open market.

Lacquer (clear).Obtainable in the market as brushing lacquers (clear).

Floor varnish (4 hr.).A special type of floor varnish which dries toextreme hardness in four hours; obtainable on the market.

Pamyfin (M. P. 55 0.) .Prepared by dissolving three pounds of paraflinin one gallon of an appropriate vehicle, as for example, carbontetrachloride or gasoline.

Gal m ambia-A 20 per cent solution of commercial powdered gum arabic inwater.

Gelatin-A 10 per cent solution of commercial crude gelatin in water.

Water-glass (sodium siZz'cate).Oommercial sirupy water-glass diluted inthe proportion of 250 parts of water-glass to 25 parts of water.

For use in making the desired tests, miniature tight cedar closets, orboxes (4: in. by 8 in. by 12 in.) with a hinged lid, were constructed ofinch red cedar heart wood. The coatings were applied to the exterior ofthe boxes as uniformly as possible by means of a flat varnish brush. Thecoated boxes together with an uncoated box as a check were set aside andkept in a warm room for a period of several months, after which acareful examination of each was made.

Examination of the boxes after such exposure at temperatures between 70and 90 F. showed that all the coatings effectively sealed the wood andprevented the escape of the cedar oil, no odor of cedar beingperceptible on the outside of the boxes. The interior of the boxes hadan unusually strong odor of cedar. The check box with no coating had adistinct odor of cedar which indicated that the wood was still exhalingodor into the atmosphere.

Since the appearance of the Wood after the application of the coatingshas an important bearing on the practicability of the various materialsused, a careful analysis of the appearance in each instance was made.

The box coated with paraflin seemed the most natural in appearance, thered color of the cedar apparently being unchanged; also there was atotal absence of gloss.

The boxes coated with gum arabic and gelatine, respectively, were alsopractically unchanged in color but both were slightly glossy.

The lacquer-coated box preserved the original red color to a markeddegree with only very slight gloss apparent.

Orange shellac slightly intensified the red ous solutions, dried byevaporation of themoisture in from 1 to 2 hours.

An approximate estimate of the cost of these materials was made, basedon the current'wholesale price of the materials used. The cost ofapplication was not estimated because of the fact that by mechanicalmeans, such as would be used on a factory scale, it would beconsiderably less than application by hand.

Parafiin, lacquer, orange shellac and floor varnish are most effectivelyand economically applied by spraying or atomizing, while the othercoatings could probably be less satisfactorily applied in this manner.

From the experiments with these materials extending over a period oftime, I have'selected paraffin as the coating especially desirable forthe purpose. While I advocate the use of paraflin I do not wish to berestricted to its use alone. Paraflin has the advantage over othermaterials because of its low cost, and the desirable feature ofefl'ectiveness, quick drying and non-sticky qualities, without changing,obscuring or hiding the color of the originalwood.

The non-sticky quality. of the coating is very important because of thefact that the boards are put up for sale in packages of practicallyairtight character and oftentimes remain in these packages for manymonths. Under these circumstances many of the coatings which otherwisewould be reasonably practicable become impracticable on account of theirtendency to become sticky and cause the boards to stick together in thepackage,

injuring or destroying their value for the purposes for which they aredesigned. When dissolved in carbon tetrachloride the hazard in itsapplication due to inflammability is ever," should be more than offsetby the superior quality and effectiveness of the cedar lining for thepurpose. p

Having thus fully described my said invention, what I claim as new anddesire-to secure by Letters Patent, is: 1. A liningfor containers suchas closets and chests consisting of cedar boards one surface of which iscoated with a transparent sealing substance comprising paraflin whichsubstance is adapted to seal the pores of the wood a ainst the escape ofthe volatile oil or aroma ut at the same time leave the wood surfaceexposed to view, and the other surface of which is left uncoated wherebythe volatile oil or aroma of the cedar may escape freely into theinterior of containers lined therewith. 2. A closed receptacle linedwith cedar boards the face of the lining boards next to 2 the walls ofthe receptacle being coated with a transparent non-adhesive sealingsubstance comprising paraffin to vprevent the escape through such sideof the volatile oils or aroma of the cedar, and the inner face'of suchlining '25 boards being left uncoa'tedwhereb'y the volatile oil or aromaof the cedar may escape freely into the interior of the receptacle.

. FRANK RABAK.

